In contrast to polyethylene, poly(alkyl ethylenes) have a series of disadvantages for thermoplastic processing, such as an increased instability of the melt and, associated therewith, a smaller processing window. Compared to polyethylene, unmodified poly(alkyl ethylenes) can be processed only at a significantly lower rate.
Poly(ethyl ethylenes) of improved processability are attained by the synthesis of poly(ethyl ethylene co-ethylene) copolymers (Natta, G., J. Polymer Sci. 51 (1961), 387-398; Chim. Ind. (Milano) 41 (1959), 764; Yu, T., J. Plastic Film Sheeting 10(1994) 1, 539-564), as well as by grafting with styrene, vinyl chloride (Natta, Polymer Sci. 34 (1959), 685-698) or acrylonitrile (U.S. Pat. No. 3,141,862). Blends of poly(ethyl ethylene) and polyethylene likewise have favorable processing properties (Hwo, C., J. Plast. Film Sheeting 3 (1987), 245-260; Kishore, K., Polymer 27 (1986), 337-343).
It is furthermore known that the instability of poly(methyl ethylene) melts can be decreased by additions of polyethylene (Ramsteiner, F., Polymer 24(1983), 365-370), polyethylene/poly(ethylene co-methylethylene) mixtures (Wasiak, A., ANTEC 1992, 1265-1266) or poly(ethylene co-acetoxyethylene) (Gupta, A. J. Appl. Polymer. Sci. 46(1992), 281-293). Enlarging the processing window of poly(methyl ethylene) is also brought about by treating the powder in the solid phase with ionizing radiation (EP 190889), peroxides (EP 384431) or monomer/peroxide mixtures (EP 437808). A treatment of poly(methyl ethylene)/polyethylene melts with peroxides is also known (Xanthos, M., Adv. Polym. Techn. 11(1992)4, 295-304).
Known methods for decreasing the melt instability of poly(isobutyl ethylene) are the synthesis of poly(isobutyl ethylene co-ethylene) copolymers (Yu, T., J. Plast. Film Sheeting 10 (1994)1, 539-564), poly(isobutyl ethylene co-hexyl ethylene ) copolymers and poly(isobutyl ethylene co-hexadecylethylene) copolymers (Campbell, J. Appl. Polymer Sci. 5 (1961)4, 184-190; Hambling, J., Rubber Plast. Age 49(1968) 3, 224-227), of poly(isobutyl ethylene co-phenylethylene) copolymers (Krenzel, V., Plast. Massy (1972)3, 57-59; Kissin, Y., Eur. Polymer J. 8 (1972)3, 487-499) as well as the synthesis of poly(isobutyl ethylene g-phenylethylene) graft copolymer (Wilson, J., J. Macromol. Sci. A6 (1972)2, 391-402).
Also known is the cross linking of poly(methyl ethylene co-ethylene), poly(methyl ethylene) and poly(acetyl ethylene co-ethylene) by irradiation to increase the thermoforming stability and the modulus (N. Brooks, J. Irradiation Techn. 1(1983)3, 237-257). Furthermore, investigations have been made of the absorption of monomers by powdery poly(alkyl ethylenes) (Rxc3xa4tzsch, M., Angew. Makromol. Chemie 229 (1995), 145-158).
It is a disadvantage of these methods that the advantageous material properties of poly(alkyl ethylenes), such as thermoforming stability, transparency and modulus, are decreased by the high proportion of modifying components during the copolymerization, grafting and alloying.
The invention is based on the problem of improving the processing properties of poly(alkyl ethylenes), so as to obtain the latter with advantageous material properties. This problem was surprisingly solved by the structural isomerization of poly(alkyl ethylenes) for which poly(alkyl ethylenes) of different chain length are linked by polymeric bridging segments into structurally isomeric poly(alkyl ethylene) with an H and a Y structure.
The poly (alkyl ethylenes) of the present invention and a process for making the same are described herein.
The "psgr" index has proven to be a suitable criterion for characterizing the processing behavior of poly(alkyl ethylenes):
"psgr"=Tmxc3x97xcex94Hmxc3x97xcex2xc3x97"xgr"xc3x97Tgxe2x88x921 (kJ/mole/degree) 
in which
Tm=melting temperature (xc2x0K.)
xcex94Hm=heat of fusion (kJ/mole)
xcex2=coefficient of linear thermal expansion at 25xc2x0 C. (1/degree)
"xgr"=threshold value
Tg=glass transition temperature (xc2x0K.)
The melting temperature (Tm(xc2x0K.) and heat of fusion DHm (kJ/mole) are determined according to the methods of the DIN 51004 or ISO 3146. The coefficient of linear thermal expansion b (1/degree) at 24xc2x0 C. is determined according to the method of DIN 53752. The threshold value x is determined by the MFI determination according to the method of the ISO 1131 by determining the strand diameter of the structurally isomeric polyalkylethylene dI (mm) produced, as well as the strand diameter of the unmodified polyalkylethylene starting material dA (mm) and forming the ratio dI/dA. The glass transition temperature is determined by the method of DIN 61006.
For the starting materials (unmodified polyalkylethylene), the melting temperature, glass transition temperature, heat of fusion and coefficient of linear thermal expansion xcex2 can be taken from tabulated values, such as those of Brandrup-Immergut xe2x80x9cPolymer Handbookxe2x80x9d, John Wiley and Sons, New York, 1989 (ISBN 0-471-81244-7).
Pursuant to the invention, the poly(alkyl ethylenes), with an H and a Y structure and a "psgr" index of 2xc3x9710xe2x88x923 to 8xc3x9710xe2x88x923 (kJ/mole/degree), have significantly more advantageous processing properties than do unmodified poly(alkyl ethylenes). For example the "psgr" value is of the order of 1.88xc3x9710xe2x88x923 (kJ/mole/degree) for poly(isobutyl ether) and 1.84xc3x9710xe2x88x923 (kJ/mole/degree) for poly (ethyl ethylene).
Poly(alkyl ethylenes) with an H structure are macromers of the structure 
wherein
R1=C1 to C4 alkyl, R2=H, t/u=0.03 to 30, R3=C1 to C4 alkyl or H, R4=H, C1 to C4 alkyl, halogen or aryl, particularly phenyl, R5=H or C1 to C4 alkyl and y+z=150 to 3,000.
"Xgr"=polymeric bridging segments comprising acrylic acid, C4 to C12 acrylic acid derivatives, C3 to C21 allyl compounds, C8 to C14 diacrylates, C7 to C16 diallyl compounds, C4 to C10 dienes, C9 to C15 dimethacrylates, C7 to C10 divinyl compounds, C3 to C16 monovinyl compounds, C12 to C17 polyacrylates, C15 to C21 polymethacrylates, C9 to C12 triallyl compounds and/or macromers comprising oligobutadienes, polysiloxanes and/or polyethers.
Poly(alkyl ethylenes) with a Y structure are macromers having the structure 
in which R=C1 to C4 alkyl, R2=H, R3=C1 to C4 alkyl or H, R4 =H, C1 to C4 alkyl, halogen or aryl, particularly phenyl, R5=H or C1 to C4 alkyl, y+z=150 to 3,000, t/u=0.03 to 30 and w=250 to 5,000.
"Xgr"=polymeric bridging segments based on acrylic acid, C4 to C12 acrylic acid derivatives, C3 to C21 allyl compounds, C8 to C14 diacrylates, C7 to C16 diallyl compounds, C4 to C10 dienes, C9 to C15 dimethacrylates, C7 to C10 divinyl compounds, C3 to C16 monovinyl compounds, C12 to C17 polyacrylates, C15 to C21 polymethacrylates, C9 to C12 triallyl compounds and/or macromers based on oligobutadienes, polysiloxanes and/or polyethers.
The proportion of polymeric bridging elements in the poly(alkyl ethylenes) with H and Y structures is 0.1 to 5% by weight.
Due to the structural isomerization of poly(alkyl ethylenes) to structurally isomeric poly(alkyl ethers) with H and Y structures, a chain arrangement, which greatly decreases the melt instability of the poly(alkyl ethylenes), is achieved in the melt.
Poly(alkyl ethylenes) with an H and a Y structure are preferred, in which R1 and R3 are formed by ethyl, methyl or isobutyl groups, R2 and R5 are formed by H and R4 is formed by ethyl, n-butyl, methyl or isobutyl groups or by H or Cl.
Mixtures of these structurally isomeric poly(alkyl ethylenes) also have these inventive properties. Preferred "psgr" values lie between 2.5xc3x9710xe2x88x923 and 6xc3x9710xe2x88x923 (kJ/mole/degree).
Suitable monovinyl compounds for the bridging segments "Xgr" are p-acetoxystyrene, aminostyrene, t-butylstyrene, bromostyrene, chlorostyrene, dichlorostyrene, m-diethylaminoethylstyrene, diethylene glycol monovinyl ether, dimethoxystyrene, dimethylstyrene, ethoxystyrene, ethylstyrene, ethyl vinyl acetate, ethyl vinyl ether, ethylvinylpyridine, fluorostyrene, 2-hydroxybutylstyrene, 2-hydroxypropylstyrene, m-hydroxystyrene, isopropylstyrene, methoxystyrene, methyl-chlorostyrene, xcex1-methylstyrene, m-methylstyrene, p-methylstyrene, methyl vinyl acetate, methyl vinyl ether, methylvinylpyridine, 4-phenoxystyrene, phenyl vinyl ether, styrene, trimethoxystyrene, trimethylstyrene, vinyl acetate, vinyl acetoxy methyl ketone, vinyl adipate, 9-vinyl anthracene, vinyl benzoate, vinyl butyl ether, vinyl butyl ketone, vinyl butyrate, vinyl carbazole, vinyl cyanoacetate, vinyl dodecyl ether, vinyl ether, vinylethyldiethoxysilane, vinyl ethyl ether, vinyl ethylene glycol glycidyl ether, vinyl ethylhexyl ether, vinyl ethyl ketone, vinyl formate, vinylfuran, vinyl hexyl ether, vinylimidazole, vinyl isobutyl ether, vinyl isocyanate, vinyl isopropyl ether, vinyl isopropyl ketone, vinyl laurate, vinylmethyldiacetoxysilane, vinylmethyldiethoxy-silane, vinyl methyl ether, vinyl methyl ketone, vinylnaphthalene, vinyl octadecyl ether, vinyl octyl ether, N-vinyloxazolidone, vinyl pelargonate, o-vinylphenol, vinyl-phenyldimethylsilane, vinyl phenyl ether, vinyl phenyl ketone, 5-vinylpicoline, vinyl propionate, N-vinylpyridine, N-vinylpyrrolidone, vinyl stearate, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl-tris(trimethoxysiloxy)silane and/or vinyltrimethylsilane in amounts of 1.5% to 5% by weight.
Suitable as divinyl compounds for the polymeric bridging segments "Xgr" are divinylaniline, m-divinylbenzene, p-divinylbenzene, diethylene glycol divinyl ether, divinylpentane, divinylpropane and/or 1,3-divinyl-1,1,3,3-tetramethyldisiloxane in amounts of 0.1% to 2% by weight.
Polymeric bridging segments "Xgr" comprising allyl compounds include monomeric units such as allyl acetate, allyl acrylate, allyl alcohol, allylbenzene, allyl benzyl ether, 3-allyl-1-butene, allyl butyl ether, allyl cyanurate, allylcyclohexane, allyl diethyl ketone, 4-allyl-2,6-dimethoxyphenol, allyldimethylchlorosilane, allyl epoxy propyl ether, allyl ethyl ether, allyl glycidyl ether, allyl glycidyl hexyl hydrophthalate, allyl glycidyl phthalate, allyl heptanoate, allyl hexanoate, allyl methacrylate, allylmethoxyphenol, allyl methyl ether, allyl methyl maleate, allyloxy-2,3-propylene glycol, N-allyl stearamide, allyl tolyl ether, allyltrichlorosilane, allyltriethoxysilane, allyltrimethoxysilane, allyltrimethylsilane, allyltriphenylsilane and/or allyl vinyl ether in amounts of 0.2% to 4.5% by weight, based on the inventive poly(alkyl ethylenes) with H and Y structures.
Diacrylates or dimethacrylates suitable for the polymeric bridging segments "Xgr" are ethylene glycol diacrylate, propylene glycol diacrylate, trimethylene glycol diacrylate, butylene glycol diacrylate, dihydroxypentane diacrylate, dihydroxyhexane diacrylate, dihydroxyoctane diacrylate, diglycol diacrylate and/or triglyol diacrylate and dimethacrylates such as ethylene glycol dimethacrylate, propylene glycol dimethacrylate, trimethylene glycol dimethacrylate, butylene glycol dimethacrylate, dihydroxypentane dimethacrylate, dihydroxyhexane dimethacrylate, dihydroxyoctane dimethacrylate, diglycol dimethacrylates and/or triglycol dimethacrylate in amounts of 0.1% to 1.6% by weight.
Glycerin triacrylate, trimethylolpropane triacrylate and/or penta-erythritol tetraacrylate, in amounts of 0.1% to 1.2% by weight, are suitable as polyacrylates for the polymeric bridging segments "Xgr".
Aside from polymeric bridging segments "Xgr" comprising acrylic acid, polymeric bridging segments "Xgr" preferably have acrylic acid derivatives, such as acrylamide, acrylonitrile, benzyl acrylate, butyl acrylate, cyclohexyl acrylate, N,N-dimethylacrylamide, dodecyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-ethoxyethyl acrylate, glycidyl acrylate, hydroxyethyl acrylate, isopropyl acrylate, 2-methoxyethyl acrylate, 4-methoxybenzyl acrylate, methyl acrylate, sodium acrylate, N-t-butoxycarbonyl-2-aminoethyl acrylate, octyl acrylate, phenylmethyl acrylate, phenyl acrylate, n-propyl acrylate and/or tetrahydrofurfuryl acrylate, in amounts of 0.2% to 1.8% by weight, based on the inventive poly(alkyl ethylenes) with H and Y structures.
As diallyl compounds for the polymeric bridging segments "Xgr", diallyldimethylsilane, diallyl(2-hydroxy-3-phenoxypropyl) isocyanurate, diallyl cyanurate, diallylcyanoethyl isocyanurate, diallyl cyanamide, diallyl maleate, diallylmelamine, diallyl phthalate and/or N,Nxe2x80x20 diamide of diallyltartaric acid in amounts of 0.2% to 1.8% by weight are suitable.
Polymeric bridging segments "Xgr" comprising dienes include monomeric units, such as butadiene, butadiene-1-carboxylic acid, chloroprene, 1,3-cyclohexadiene, 1,5-cyclohexadiene, cyclopentadiene, 2,3-dimethylbutadiene, 1-ethoxybutadiene, 1,4-heptadiene, 1,4-hexadiene, 1,6-hexadiene, isoprene, norbornadiene and/or 1,4-pentadiene in amounts of 0.1% to 1.6% by weight, based on the inventive poly(alkyl ethylenes) with H and Y structures.
Preferred polymeric bridging segments "Xgr", comprising polymethacrylates include monomeric units such as glycerin trimethacrylate, trimethylolpropane trimethacrylate and/or pentaerythritol methacrylate in amounts of 0.1% to 1.2% by weight.
As triallyl compounds for polymeric bridging segments "Xgr", triallyl citrate, triallyl cyanurate, triallyl isocyanurate and/or triallyl phosphine, in amounts of 0.1% to 1.4% by weight, are suitable.
Suitable macromers for polymeric bridging segments "Xgr" comprise oligobutadienes, polysiloxanes and/or polyethers with terminal acrylic, allyl, isocyanate, oxazoline or vinyl groups, in amounts of 0.8% to 5% by weight, based on the inventive poly(alkyl ethylenes) with H and Y structures.
Pursuant to the invention, mixtures of 3% to 97% of poly(alkyl ethylenes) with H and Y structures, 97% to 3% of unmodified poly(alkyl ethylenes), 0.001% to 2.5% of stabilizers and optionally 0.1% to 1% of antistatic materials, 0.2% to 3% of pigments, 0.05% to 1% of nucleating agents, 5% to 40% of fillers, 2% to 20% of flame retardants and/or 0.001% to 1% of processing aids also have a better processability than do unmodified poly(alkyl ethylenes); the Y index for these mixtures is of the order of 2xc3x9710xe2x88x923 to 7.8xc3x9710xe2x88x923 (kJ/mole/degree).
As stabilizers, preferably mixtures of 0.01% to 0.6% by weight of phenolic antioxidants, 0.01% to 0.6% of processing stabilizers based on phosphites, 0.01% to 0.6% of high-temperature stabilizers based on disulfides and thioethers and 0.01% to 0.8% of sterically hindered amines (HALS) are used.
Suitable phenolic antioxidants are 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-isoamylphenol, 2,6-di-t-butyl-4-ethylphenol, 2-t-butyl-4,6-diisopropylphenol, 2,6dicyclopentyl-4-methylphenol, 2,6-di-t-butyl-4-methoxymethylphenol, 2-t-butyl-4,6-dioctadecylphenol, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-4,4-hexadecyloxyphenol, 2,2xe2x80x2-methylene-bis(6-t-butyl-4-methylphenol), 4,4xe2x80x2-thio-bis-(6-t-butyl-2-methylphenol), octadecyl 3(3,5-di-t-butyl-4-hydroxyphenyl-propionate, 1,3,5-trimethyl-2,4,6-tris(3xe2x80x2,5xe2x80x2-di-t-butyl-4-hydroxybenzyl)benzene and/or pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate.
As HALS compounds, bis-2,2,6,6-tetramethyl-4-piperidyl sebacate and/or poly((1,1,3,3-tetramethylbutyl)-imino)-1,3,5-triazine-2,4,diyl)(2,2,6,6-tetra-methylpiperidyl)-amino)-hexamethylene-4-(2,2,6,6-tetramethyl)piperidyl)-imino) are particularly suitable.
As processing aids, calcium stearate, magnesium stearate and/or waxes can be used.
Pursuant to the invention, structurally isomeric poly(alkyl ethylenes) are synthesized either according to an irradiation method or according to a melt reaction method or according to a solid phase reaction method.
For the irradiation, the powdery mixtures of 95% to 99.98% by weight of poly(C1 to C4 alkyl ethylenes) and 0.02% to 5% by weight of acrylic acid, acrylic acid derivatives, allyl compounds, diacrylates, diallyl compounds, dienes, dimethacrylates, divinyl compounds, macromers with terminal acrylic, allyl, isocyanate, oxazoline or vinyl groups based on oligobutadienes, polysiloxanes or polyethers, monovinyl compounds, polyacrylates, polymethacrylates and/or triallyl compounds are exposed pursuant to the invention in a fluidized bed preferably under inert conditions, at 300xc2x0 to 500xc2x0 K. This takes place optionally in the presence of additional conventional auxiliary materials, particularly of 0.01% to 0.6% by weight of phenolic antioxidants, 0.01% to 0.6% by weight of high-temperature stabilizers based on disulfides and polyethers, 0.01 to 0.6% of processing stabilizers based on phosphites and/or 0.01% to 0.6% of sterically hindered amines (HALS), 0.1% to 1% of antistatic agents, 0.2% to 3% pigments, 0.05% to 1% of nucleating agents, 5% to 40% of fillers, 2% to 20% of flame retardants and/or 0.001% to 1% of processing aids. The irradiation process includes the following steps:
a) A first step of the reaction takes place preferably in fluidized bed reactors with continuous feeding of starting materials and discharging of reaction products. It uses an ionizing radiation having an energy of 150 to 10,000 KeV at an irradiation dose of 0.5 to 80 KGy. This is accomplished by, for example, nuclide irradiation equipment with cobalt 60 as radiation source, electron beam accelerators of the Cockcroft-Walton type with radiation energies of 300 to 4500 KeV or by electron beam accelerators of the linear accelerator type with beam current energies of 1,000 to 10,000 KeV.
b) A second step of the reaction includes a thermal treatment of the irradiated, powdery mixtures at 380xc2x0 to 550xc2x0 K. This can take place in, for example, extruders at temperatures ranging from 410xc2x0 to 550xc2x0 K. and at reaction times of 2 to 10 minutes or in the solid phase at temperatures ranging from 380xc2x0 to 500xc2x0 K. at reaction times from 5 to 60 minutes. It is possible to add, in addition, conventional stabilizers in concentrations of 0.01% to 0.6% before the thermal treatment.
For the melt reaction method, poly(C1 to C4 alkyl ethylenes) are caused to react by a continuous method in the extruder, preferably under inert conditions. The melt reaction method includes the following steps:
a) A first step of the reaction employs 0.01% to 3% by weight of acyl peroxides, alkyl peroxides, hydroperoxides and/or peresters, which are either drummed up on the poly(alkyl ethylenes) in the kneader and metered together or metered as a solution into the poly(alkyl ethylene) melt in zones 2 to 4 of the extruder.
b) In the second step of the reaction, 0.01% to 5% by weight of acrylic acid or acrylic acid derivatives, allyl compounds, diacrylates, diallyl compounds, dienes, dimethacrylates, divinyl compounds, macromers with terminal acrylic, allyl, isocyanate, oxazoline or vinyl groups and based on oligobutadienes, polysiloxanes or polyethers, monovinyl compounds, polyacrylates, polymethacrylates and/or triallyl compounds, are caused to react in the presence of 0.001% to 3.0% by weight of acyl peroxides, alkyl peroxides, hydroperoxides and/or peresters. The reaction optionally takes place in the presence of conventional auxiliary materials, particularly 0.01 to 0.6% by weight of phenolic antioxidants, 0.01% to 0.6% by weight of high-temperature stabilizers based on disulfides and polyethers, 0.01% to 0.6% of processing stabilizers based on phosphites and/or 0.01% to 0.8% of sterically hindered amines (HALS), 0.1% to 1% of antistatic agents, 0.2% to 3% of pigments, 0.05% to 1% of nucleating agents, 5% to 40% of fillers, 2 to 20% of flame retardants and/or 0.001% to 1% of processing aids at temperatures of 140xc2x0 to 320xc2x0 C. The radical-forming agents and the monomers are metered in over separate metering equipment and/or jointly as a solution into the poly(alkyl ethylene) melt in zones 3 to 6 of the extruder, optionally with a further portion of poly(alkyl ethylene).
The solid-phase continuous method occurs preferably under inert conditions. The following steps are employed in the solid phase as a continuous method:
a) Powdery poly(C1 to C4 alkyl ethylenes) are subjected, pursuant to the invention, in a first step of the method at 290xc2x0 to 500xc2x0 K. in reactors with rotating equipment and circulating carrier gas, to a sorption with 0.05 to 3% by weight of acyl peroxides, alkyl peroxides, hydroperoxides and/or peresters as well as 0.05% to 5% by weight of acrylic acid, acrylic acid derivatives, allyl compounds, diacrylates, diallyl compounds, dienes, dimethacrylates, divinyl compounds, monovinyl compounds, polyacrylates, polymethacrylates and/or triallyl compounds, which were introduced over vaporizing equipment into the carrier-gas stream.
b) The powdery mixtures, in a second step of the method, optionally with the addition of conventional auxiliary materials, particularly of 0.01% to 2.5% of stabilizers, 0.1% to 1% of antistatic agents, 0.2% to 3% of pigments, 0.05% to 1% of nucleating agents, 5% to 40% of fillers, 2% to 20% of flame retardants and/or 0.001% to 1% of processing aids, are heated in the feed region of the screw injection molding machine, particularly twin-screw extruders or single-screw extruders with plunger screw, to the decomposition temperature of the radical-forming agent and subsequently melted at reaction temperatures of 415xc2x0 to 596xc2x0 K. and granulated.
As poly(alkyl ethylenes), preferably poly(ethyl ethylenes) with glass transition temperatures of 242xc2x0 to 250xc2x0 K. and molecular weights (Mw) ranging from 2xc3x97104 to 3xc3x97106, poly(ethyl ethylene co-ethylene) copolymers, containing 3 to 45 mole percent of ethylene in the copolymer, poly(ethyl ethylene co-methylethylene) copolymers containing 3 to 97 mole percent of methylethylene in the copolymer, poly(isobutylenes) with glass transition temperatures of 295xc2x0 to 303xc2x0 K. and densities ranging from 0.813 to 0.832 g/cc at 25xc2x0 C., poly(isobutyl ethylene co-n-butylethylene) copolymers with an n-butylethylene portion of 3 to 97 mole percent, poly(isobutyl ethylene) copolymers with an ethylene portion in the copolymer of 3 to 45 mole percent, poly(methyl ethylenes) with glass transition temperatures ranging from 259xc2x0 to 268xc2x0 K. and molecular weights (Mw) ranging from 1xc3x97105 to 8xc3x97106 and/or poly(methyl ethylene co-ethylene) copolymers with an ethylene potion in the copolymer of 3 to 45 mole percent, are used.
Examples of the peroxides used are:
acyl peroxides, such as benzoyl peroxide, 4-chlorobenzoyl peroxide, 3-methoxybenzoyl peroxide and methylbenzoyl peroxide;
alkyl peroxides, such as acetyl peroxide, allyloxypropionyl peroxide, allyl-t-butyl peroxide, benzoyl peroxide, 2,2-bis(t-butylperoxybutane), 1,1-bis-(t-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4,bis(t-butylperoxy) valerate, diisopropyl-aminomethyl-t-amyl peroxide, d-methylaminomethyl-t-amyl peroxide, diethyl-aminomethyl-t-butyl peroxide, dimethylaminomethyl-t-butyl peroxide, dinitro-benzoyl peroxide, 1,1-di-(t-amylperoxy)cyclohexane, methoxybenzoyl peroxide, methylbenzoyl peroxide, t-amyl peroxide, t-butylcumyl peroxide, t-butylpermaleic acid, t-butyl peroxide, 1-hydroxybutyl-n-butyl peroxide and/or succinoyl peroxide;
hydroperoxides, such as decalin hydroperoxide and/or tetralin hydroperoxide;
ketone peroxides, such as methyl ethyl ketone hydroperoxide;
peresters and peroxycarbonates, such as butyl peracetate, cumyl peracetate, cumyl perpropionate, cyclohexyl peracetate, di-t-butyl peradipate, di-t-butyl perazelate, di-t-butyl perglutarate, di-t-butyl perphthalate, di-t-butyl persebacate, 4-nitrocumyl perpropionate, 1-phenylethyl perbenzoate, phenylethylnitroperbenzoate, t-butyl-bicyclo-(2,2,1) heptapercarboxylate, t-butyl-4-carbomethoxy perbutyrate, t-butyl-cyclobutane percarboxylate, t-butylcyclohexyl peroxycarboxylate, t-butylcyclo-pentyl percarboxylate, t-butylcyclopropane percarboxylate, t-butyldimethyl percinnamate, t-butyl-2-(2,2-diphenylvinyl perbenzoate, t-butyl-4-methoxy perbenzoate, t-butyl perbenzoate, t-butylcarboxycyclohexane, t-butyl pernaphthoate, t-butyl peroxyisopropyl carbonate, t-butyl pertoluate, t-butyl-1-phenylcyclopropyl percarboxylate, t-butyl-2-propyl 2-perpentenoate, t-butyl-1-methylcyclopropyl percarboxylate, t-butyl-4-nitrophenyl peracetate, t-butylnitrophenyl peroxycarbamate, t-butyl-N-succinimido percarboxylate, t-butyl percrotonate, t-butyl permaleate, t-butyl permethacrylate, t-butyl peroctoate, t-butyl peroxyisopropylcarbonate, t-butyl perisobutyrate, t-butyl peracrylate and/or t-butyl perpropionate.
Examples of the monomers used are:
acrylic acid derivatives, such as acrylamide, acrylonitrile, benzyl acrylate, butyl acrylate, cyclohexyl acrylate, N,N-dimethylacrylamide, dodecyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-ethoxyethyl acrylate, glycidyl acrylate hydroxy-ethyl acrylate, isopropyl acrylate, 2-methoxyethyl acrylate, 4-methoxybenzyl acrylate, methyl acrylate, sodium acrylate, N-t-butoxycarbonyl-2-aminoethyl acrylate, octyl acrylate, phenylmethyl acrylate, phenyl acrylate, n-propyl acrylate and/or tetrahydrofurfuryl acrylate;
diallyl compounds, such as diallyldimethylsilane, diallyl(2-hydroxy-3-phenoxy-propyl) isocyanurate, diallyl cyanurate, diallylcyanoethyl isocyanurate, diallyl cyanamide, diallyl maleate, diallylmelamine, diallyl phthalate and/or N,Nxe2x80x2-diallyl tartaramide;
dimethacrylates, such as ethylene glycol dimethacrylate, propylene glycol dimethacrylate, trimethylene glycol dimethacrylate, butylene glycol dimethacrylate, dihydroxypentane dimethacrylate, dihydroxyhexane dimethacrylate, dihydroxy-octane dimethacrylate, diglycol dimethacrylate and/or triglycol dimethacrylate;
dienes, such as butadiene, butadiene-1-carboxylic acid, chloroprene, cyclohexadiene, cyclopentadiene, 2,3-dimethylbutadiene, 1-ethoxy butadiene, 1,4-heptadiene, 1,4-hexadiene, 1,6-hexadiene, isoprene, norbornadiene and/or pentadiene;
polymethacrylates, such as glycerin trimethacrylate, trimethylolpropane trimethacrylate and/or pentaerythritol tetramethacrylate;
triallyl compounds, such as triallyl citrate, triallyl cyanurate, triallyl isocyanurate and/or triallylphosphene; monovinyl compounds, such as acetoxystyrene, aminostyrene, t-butylstyrene, bromostyrene, chlorostyrene, dichlorostyrene, m-diethylaminoethylstyrene, diethylene glycol monovinyl ether, dimethoxystyrene, dimethylstyrene, ethoxystyrene, ethylstyrene, ethylvinyl acetate, ethylvinyl ether, ethylvinyl-pyridine, fluorostyrene, 2-hydroxybutylstyrene, 2-hydroxypropylstyrene, m-hydroxystyrene, isopropylstyrene, methoxystyrene, methylchlorostyrene, xcex1-methylstyrene, m-methylstyrene, p-methylstyrene, methylvinylacetyl, methylvinyl ether, methylvinylpyridine, 4-phenoxystyrene, phenylvinyl ether, styrene, trimethoxy styrene, trimethylstyrene, vinyl acetate, vinyl acetoxymethyl ketone, vinyl adipate, 9-vinylanthracene, vinyl benzoate, vinyl butyl ether, vinyl butyl ketone, vinyl butyrate, vinylcarbazol, vinylcyanoacetate, vinyl dodecyl ether, vinyl ether, vinylethoxydiethoxysilane, vinyl ethyl ether, vinyl ethylene glycol glycidyl ether, vinyl ethylhexyl ether, vinyl ethyl ketone, vinyl formate, vinyl furan, vinyl hexyl ether, vinylimidazole, vinyl isobutyl ether, vinyl isocyanate, vinyl isopropyl ether, vinyl isopropyl ketone, vinyl laurate, vinylmethyldiacetoxysilane, vinylmethyldiethoxysilane, vinyl methyl ether, vinyl methyl ketone, vinylnapthalene, vinyl octadecyl ether, vinyl octyl ether, N-vinyloxazolidone, vinyl pelargonate, o-vinylphenol, vinylphenyldimethylsilane, vinyl phenyl ether, vinyl phenyl ketone, 5-vinylpicoline, vinyl propionate, N-vinylpyridine, N-vinylpyrrolidone, vinyl stearate, vinyltriethoxysilane, vinyltrimethoxysilane, vinyl-tris(trimethoxysiloxy)silane and/or vinyltrimethylsilane;
divinyl compounds, such as divinylaniline, m-divinylbenzenes, p-divinylbenzenes, diethylene glycol divinyl ether, divinylpentane, divinylpropane and/or 1,3-divinyl-1,1,3,3,-tetramethyldisiloxane;
allyl compounds, such as allyl acetate, allyl acrylate, allyl alcohol, allylbenzene, allyl benzyl ether, 3-allyl-1-butene, allyl butyl ether, allyl cyanurate, allycyclo-hexane, allyl diethyl ketone, 4-allyl-2,6-dimethoxyphenol, allyldimethylchloro-silane, allyl epoxypropyl ether, allyl ethyl ether, allyl glycidyl ether, allyl glycidyl hexahydrophthalate, allyl glycidyl phthalate, allyl heptanoate, allyl hexanoate, allyl methacrylate, allylmethoxyphenol, allyl methyl ether, allyl methyl maleate, allyloxy-2,3-dihydroxypropane, N-allyl stearamide, allyl tolyl ether, allyltrichloro-silane, allyltriethoxysilane, allyltrimethoxysilane, allyltrimethylsilane, allyltriphenylsilane and/or allyl vinyl ether;
diacrylates, such as ethylene glycol diacrylate, propylene glycol diacrylate, trimethylene glycol diacrylate, butylene glycol diacrylate, dihydroxypentane diacrylate, dihydroxyhexane diacrylate, dihydroxyoctane diacrylate, diglycol diacrylate and/or triglycol diacrylate;
macromers, based on oligobutadienes, polysiloxanes and/or polyethers with terminal acrylic, allyl, isocyanate, oxazoline or vinyl groups.
As stabilizers, mixtures of 0.01% to 0.6% by weight of phenolic antioxidants, 0.01% to 0.6% of processing stabilizers comprising phosphites, 0.01% to 0.6% of high-temperature stabilizers comprising disulfides and thioethers and 0.01% to 0.8% of sterically hindered amines (HALS) are preferably used.
Suitable phenolic antioxidants are 2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-isoamylphenol, 2,6-di-t-butyl-4-ethylphenol, 2-t-butyl-4,6-diisopropylphenol, 2,6-dicyclopentyl-4-methylphenol, 2,6-di-t-butyl-4-methoxymethylphenol, 2-t-butyl-4,6-dioctadecylphenol, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-4,4-hexadecyloxyphenol, 2,2xe2x80x2-methylene-bis(6-t-butyl-4-methylphenol), 4,4xe2x80x2-thio-bis-(6-t-butyl-2-methylphenol), octadecyl 3(3,5-di-t-butyl-4-hydroxy-phenol)propionate, 1,3,5-trimethyl-2,4,6-tris(3xe2x80x2,5xe2x80x2-di-t-butyl-4-hydroxybenzyl)benzene and/or pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl))-propionate.
As HALS compounds, bis-2,2,6,6-tetramethyl-4-piperidyl sebacate and/or poly-((1,1,3,3-tetramethylbutyl)-imino)-1,3,5-triazine-2,4-diyl)(2,2,6,6-tetra-methylpiperidyl)-amino)-hexamethylene-4-(2,2,6,6-tetramethyl)piperidyl)-imino) are particularly suitable.
For the irradiation method, the powdery mixtures are prepared from 95% to 99.98% by weight of poly(alkyl ethylenes) and 0.02% to 5% by weight of acrylic acid or acrylic acid derivatives, allyl compounds, diacrylates, diallyl compounds, dienes, dimethacrylates, divinyl compounds; macromers with terminal acrylic, allyl, isocyanate, oxazoline or vinyl groups and based on oligobutadienes, polysiloxanes and/or polyethers, monovinyl compounds, polyacrylates, polymethacrylates and/or triallyl compounds, preferably in kneaders, static mixers or fluidized bed reactors.
For the melt reaction method, twin-screw extruders with an L/D ratio of 30 to 45 are preferably used. Advantageous reaction temperatures for both steps of the reaction are 140xc2x0 to 250xc2x0 C. when poly(ethyl ethylene) homopolymers and copolymers are used, 165xc2x0 to 270xc2x0 C. when poly(methyl ethylene) homopolymers and copolymers are used and 240xc2x0 to 310xc2x0 C. when poly(isobutyl ethylene) homopolymers and copolymers are used.
For the solid phase reaction method, bunker supply bins are preferably suitable as reactors with rotating equipment and circulating carrier gas.
The inventive poly(alkyl ethylenes) with H and Y structures and a Y index of 2xc3x9710xe2x88x923 to 8xc3x9710xe2x88x923 (kJ/mole/degree), as well as the mixtures with unmodified poly(alkyl ethylenes), stabilizers, antistatic agents, pigments, nucleating agents, fillers, flame retardants and/or processing aids are preferably suitable for the production of films, sheets, coatings, pipes, hollow objects and foams.
The invention is explained by the following examples: